1. USGS: ‘Mineral commodity summary: rare earths’, 128–129; 2011, Reston, VA, US Geological Survey.
2. Uda T, Hirasawa M: ‘Rare earth separation and recycling process using rare earth chloride, metallurgical and materials processing: principles and technologies’, Yazawa International Symposium, Vol.3, (ed. F. Kongoliet al.), ‘Aqueous and electrochemical processing’, 2003, 373–385.
3. Okabe T, Takeda O, Fukuda K, Umetsu Y: ‘Scrap combination for recycling of valuable metals: direct extraction and recovery of neodymium metal from magnet scraps’, Yazawa International Symposium, Vol.1, (ed. F. Kongoliet al.),Metall. Mater. Process.: Principles Technol., 2003, 1079–1091.
4. Lyman JW, Palmer GR: ‘Recycling of NdFeB magnet scrap’, (report of investigations), Salt Lake City, UT, Salt Lake City Research Center, Bureau of Mines, 1993.
5. Niinae M, Yamaguchi K, Nakahiro Y, Wakamatsu T: ‘Hydrometallurgical treatment of rare earth magnet scrap’, Proc. XIX Int. Miner. Process. Congress on ‘Physical & chemical processing’, Vol. 2, Chapter 43, Chemical Processing, 229–233, 1995.